'Herd immunity' against fire? A concrete strategy

Homes made of composite block can shield others

- BY JACK FLEMMING

Photographs by GENARO MOLINA Los Angeles Times

SUNSET MESA community members gather at Karen Martinez's property as it is rebuilt with Perfect Block.

Sunset Mesa, the scenic neighborhood tucked on a bluff between Malibu and Pacific Palisades, might never be the same in the wake of the Palisades fire.

But resident Karen Martinez sees one potential change as a good thing.

The January fire torched about 80% of the community’s 500 homes — almost all of them wood-framed. Now, as residents begin the long process of rebuilding, Martinez is pushing her neighbors to chuck the lumber and build with noncombustible materials instead.

The goal? The housing equivalent of herd immunity, where enough homes are fireproof that the entire community can be protected against future fires. Your home is far safer if your next-door neighbors’ houses aren’t burning down and sending fiery debris and showers of embers into the air.

The benefits of herd immunity stretch beyond fire defense; some insurance companies have signaled that they're open to insuring more homes - at cheaper rates in neighborhoods that feature higher percentages of fireproof homes.

For the last year, Martinez, 62, has become an evangelist for insulated composite concrete forms (ICCF), a building material made from concrete and expanded polystyrene (Styrofoam). She's been holding Zoom meetings for neighbors, proselytizing just this month when she hosted a community potluck where 70 people watched her lay the first few Perfect Blocks of her fireproof home.

"I want people to know they have options," Martinez said. "We don't have to rebuild with something that's going to burn again."